传统永磁同步电机直接转矩控制系统存在磁链控制不对称、转矩脉动大等问题，该文在分析传统直接转矩控制中磁链和转矩运行轨迹及脉动的基础上，提出了一种把扇区细分和占空比控制相结合的新型永磁同步电机直接转矩控制方法。该方法将传统的6个扇区细分成18个扇区，并根据转矩误差计算出所选择电压矢量在整个采样周期中的占空比，实时调整有效电压矢量的作用时间。实验结果证明该结合扇区细分和占空比控制技术的新型永磁同步电机直接转矩控制方法与传统直接转矩控制相比，能够有效改善磁链轨迹，减小转矩脉动，改善传统直接转矩控制系统性能。

Disadvantages of traditional direct torque control (DTC) systems for permanent magnet synchronous motors (PMSM) are flux asymmetry and high torque ripples. A novel DTC strategy of PMSM combined sectors subdivision with duty ratio control is proposed based on the analysis of flux linkage and torque control trajectory and ripples. Six sectors are subdivided into eighteen sectors, the ratio between the action time of current voltage vector and the sampling time is computed and the action time of effective voltage vectors is adjusted. Experimental results verify that compared with traditional DTC, the proposed DTC strategy combined sectors subdivision with duty ratio control improves flux trajectory effectively, reduces torque ripples and improves the performance of traditional DTC.